1. Photochemical Alkene Hydrophosphination with Bis(trichlorosilyl)phosphine
Michael B Geeson, Keita Tanaka, Rachid Taakili, Rachid Benhida, Christopher C Cummins J Am Chem Soc. 2022 Aug 17;144(32):14452-14457. doi: 10.1021/jacs.2c05248. Epub 2022 Aug 4.
Bis(trichlorosilyl)phosphine (HP(SiCl3)2, 1) was prepared from [TBA][P(SiCl3)2] ([TBA]2, TBA = tetra-n-butylammonium) and triflic acid in 36% yield. Phosphine 1 is an efficient reagent for hydrophosphination of unactivated terminal olefins under UV irradiation (15-60 min) and gives rise to bis(trichlorosilyl)alkylphosphines (RP(SiCl3)2, R = (CH2)5CH3, 88%; (CH2)7CH3, 98%; (CH2)2C(CH3)3, 76%; CH2Cy, 93%; (CH2)2Cy, 95%; CH2CH(CH3)(CH2)2CH3, 82%; (CH2)3O(CH2)3CH3, 95%; (CH2)3Cl, 83%; (CH2)2SiMe3, 92%; (CH2)5C(H)CH2, 44%) in excellent yields. The products require no further purification beyond filtration and removal of volatile material under reduced pressure. The P-Si bonds of prototypical products RP(SiCl3)2 (R = -(CH2)5CH3, -(CH2)7CH3) are readily functionalized to give further phosphorus-containing products: H3C(CH2)7PCl2 (56%), [H3C(CH2)5P(CH2Ph)3]Br (84%), H3C(CH2)7PH2 (61%), H3C(CH2)5P(O)(H)(OH) (81%), and H3C(CH2)5P(O)(OH)2 (55%). Experimental mechanistic investigations, accompanied by quantum chemical calculations, point toward a radical-chain mechanism. Phosphine 1 enables the fast, high-yielding, and atom-efficient preparation of compounds that contain phosphorus-carbon bonds in procedures that bypass white phosphorus (P4), a toxic and high-energy intermediate of the phosphorus industry.
2. catena-Poly[[bis-(2,4-dichloro-benzoato)bis-(methanol-κO)cobalt(II)]-μ-4,4'-bipyridine-κN:N']
Min Young Hyun, Pan-Gi Kim, Cheal Kim, Youngmee Kim Acta Crystallogr Sect E Struct Rep Online. 2011 Dec 1;67(Pt 12):m1705. doi: 10.1107/S1600536811046149. Epub 2011 Nov 9.
In the title compound, [Co(C(7)H(3)Cl(2)O(2))(2)(C(10)H(8)N(2))(CH(3)OH)(2)](n), the Co(II) ion lies on a twofold rotation axis and is in a slightly distorted octa-hedral CdO(4)N(2) environment, formed by two O atoms from monodentate dichloro-benzoate ligands, two O atoms from methanol ligands, and two N atoms from trans-related 4,4'-bipyridine ligands. The bipyridine ligands also lies on a twofold rotation axis and bridge the Co(II) ions, forming chains extending along [010]. An intra-chain O-H⋯O hydrogen bond is observed.
3. Fe-modified Co2(OH)3Cl microspheres for highly efficient oxygen evolution reaction
Wei Wang, Yunlei Zhong, Xinyu Zhang, Sainan Zhu, Yourong Tao, Yanxin Zhang, Hongsen Zhu, Yifei Zhang, Xingcai Wu, Guo Hong J Colloid Interface Sci. 2021 Jan 15;582(Pt B):803-814. doi: 10.1016/j.jcis.2020.08.095. Epub 2020 Aug 29.
Surface self-reconstruction by the electrochemical activation is considered as an effective strategy to increase the oxygen evolution reaction (OER) performance of transition metal compounds. Herein, uniform Co2(OH)3Cl microspheres are developed and present an activation-enhanced OER performance caused by the etching of lattice Cl- after 500 cyclic voltammetry (CV) cycles. Furthermore, the OER activity of Co2(OH)3Cl can be further enhanced after small amounts of Fe modification (Fe2+ as precursor). Fe doping into Co2(OH)3Cl lattices can make the etching of surface lattice Cl- easier and generate more surface vacancies to absorb oxygen species. Meanwhile, small amounts of Fe modification can result in a moderate surface oxygen adsorption affinity, facilitating the activation of intermediate oxygen species. Consequently, the 10% Fe-Co2(OH)3Cl exhibits a superior OER activity with a lower overpotential of 273 mV at 10 mA cm-2 (after 500 CV cycles) along with an excellent stability as compared with commercial RuO2.
